Hi 🙂
I have installed Joomla Admin Tools. There is Web Application Firewall.
You have to login on secret URL. If you try regular login 3 times, you have been temporarilly banned. The same is if some bot try to use deep links, injections, etc.
I see all attempts to use deep link calls. See attachement.
I have found this for this issue: https://forum.joomla.org/viewtopic.php?t=674643
Reg
Regards,
Tom